Differential subunit composition of the G protein–activated inward-rectifier potassium channel during cardiac development
J. Clin. Invest. Bernd K. Fleischmann, et al. 114:994 doi:10.1172/JCI15925 [
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Figure 8Overexpression of Kir3.4 in early-stage atrial cardiomyocytes reconstitutes the late-stage phenotype. (
A) Left panel: I
K,ACh-mediated currents induced by CCh and recorded at potentials of _100 mV (gray trace) and 40 mV (black trace) in an early-stage cell overexpressing Kir3.4. Right panel: Steady-state I-V relation of the experiment in
A (voltage steps from _100 mV to 40 mV in 20-mV steps). (
B) Current traces and steady-state I-V relation as in
A, but recorded from a late-stage cardiomyocyte overexpressing Kir3.1. (
C) Hyperpolarization and negative chronotropy induced by CCh and reversed by tertiapin in an early-stage Kir3.4_overexpressing cardiomyocyte. (
D) CCh-induced deceleration of spontaneous APs (left axis) and reversal by tertiapin (right axis) in early-stage cardiomyocytes overexpressing Kir3.4. Data are mean ± SEM of 9 cells.
